Stana Katic beautiful but poorly cast

While beautiful, Stana Katic is an astonishingly bad choice for the character of Romana, Romana was (the character and the woman who inspired the character) BIG (like Mae West, Kerouac said), dark brunette, Jewish Romanian, always wore a braid, was intelligent and learned, warm-hearted and grounded, very sensual and physical, studied Buddhism -- Stana Katic's character has dark blond hair, styled in a ridiculously glam 2013 wavy hairstyle, is very thin, doesn't particularly project intelligence, doesn't have a humorous/amused vibe, tho in the film she's always wooting and giggling but doesn't sound like it's coming from a joyous spirit, not seemingly evolved spiritually, nor sexual. When she is walking around in bra and panties she seems sort of like a 21st Century prude, not an earth-woman/sensualist/semi-exhibitionist, as Romana was. Did the director even read the book? Did Stana Katic? Did either of them bother with a simple Google search poet Lenore Kandel who was known by, and captured quite well by, Keruoac?

Why would a director be so lame in making such a casting choice?